direnv exec not unloading previous environment

[smancill]

Issue description

It should unload, right? That's what I get from this wiki page about tmux: direnv exec / tmux would ensure direnv is unloaded, but is not happening.

Steps to reproduce

I wrote a small test case:

#!/bin/bash

mkdir -p foo
echo "export FOO=foo" > foo/.envrc

mkdir -p bar
echo "export BAR=bar" > bar/.envrc

cat << EOF > check
#!/bin/sh
echo "FOO: \$FOO"
echo "BAR: \$BAR"
EOF
chmod +x check

direnv allow foo
direnv allow bar

echo -e ">> direnv exec . ./check"
direnv exec . ./check

echo -e "\n>> direnv exec foo ./check"
direnv exec foo ./check

echo -e "\n>> cd bar"
cd bar && eval "$(direnv export bash)"

echo -e "\n>> ../check"
../check

echo -e "\n>> direnv exec ../foo ../check    # BAR is not unset"
direnv exec ../foo ../check

echo -e "\n>> direnv exec .. ../check        # BAR is not unset"
direnv exec .. ../check

echo -e "\n>> cd ../foo"
cd ../foo && eval "$(direnv export bash)"

echo -e "\n>> ../check"
../check

The output is:

$ ./test-direnv-exec
>> direnv exec . ./check
FOO:
BAR:

>> direnv exec foo ./check
direnv: loading foo/.envrc
FOO: foo
BAR:

>> cd bar
direnv: loading .envrc
direnv: export +BAR

>> ../check
FOO:
BAR: bar

>> direnv exec ../foo ../check    # BAR is not unset
direnv: loading ../foo/.envrc
FOO: foo
BAR: bar

>> direnv exec .. ../check        # BAR is not unset
FOO:
BAR: bar

>> cd ../foo
direnv: loading .envrc
direnv: export +FOO

>> ../check
FOO: foo
BAR:

It can be reproduced also if all commands are run interactively.

Technical details

• direnv version: 2.17.0
• OS release: Mac OS X (10.12.6)

[jason0x43]

Possibly the issue is here:

direnv/cmd_exec.go

Lines 48 to 61 in 40a1cb9

	// Restore pristine environment if needed
	if previousEnv, err = config.Revert(env); err != nil {
	return
	}
	previousEnv.CleanContext()
	// Load the rc
	if toLoad := findUp(rcPath, ".envrc"); toLoad != "" {
	if newEnv, err = config.EnvFromRC(toLoad, previousEnv); err != nil {
	return
	}
	} else {
	newEnv = env
	}

In the else block, newEnv is set to env (the current environment) rather than to the just-computed previousEnv.